This invention relates to an improvement of a pavement-marking tape applicator and, more particularly, to a pavement-marking tape applicator capable of readily adjusting a free end position of the tape at the start of application of the tape on the paved surface and of readily cutting the tape.
For pavement marking such as a center line on a paved surface, conventional application of coating is often replaced by use of a pavement-marking tape which is improved in reflectivity by having glass beads embedded therein.
The pavement-marking tape is usually in the form of a roll and it must be unwound from the roll and pressed against the paved surface for application on the paved surface.
For the purpose of efficiently performing such application operation, U.S. Pat. No. 4,242,173 discloses a specific apparatus made for this purpose which is shown in FIG. 10.
In this prior art apparatus, a front wheel of an applicator 2 having a handle 1 serves as a tape application roller 3 and a roll of pavement-marking tape 5 is unwindably supported in grooves 4 formed in the upper portion of the applicator 2. An unwound length of tape 5 is guided in front of the application roller 3 via a guide roller 6. By actuating a lever 8 of a tape gripping mechanism 7 constructed of a link, length of tape 5 is fed out and caused to be engaged by the application roller 3. The tape 5 can be cut by depressing a pedal 10 of cutting means 9.
In starting application of tape by causing the tape 5 to be engaged by the application roller 3 in this prior art tape application apparatus, the lever 8 of the tape gripping mechanism 7 is pushed forward to cause the foremost end portion of the gripping mechanism 7 to grip the tape 5 and pull it downwardly.
Since the tape gripping mechanism 7 feeds out a constant length of tape 5, there is likelihood that the tape 5 will be applied on the paved surface in a wrinkled state if the tape 5 is fed excessively whereas the tape 5 will not reach the paved surface and therefore will not be applied on the paved surface even if the applicator 2 is advanced, if length of tape fed out is insufficient.
Again, since the tape gripping mechanism, 7 releases the tape 5 when the tape 5 is applied on the paved surface, when the applicator 2 has stopped its advance, the tape 5 may be fed out in front of the application roller 3 in a loosened state due to inertia of rotation of the roll of tape 5 and this will cause the tape 5 to become creased in next application.
Further, the cutting means in the prior art tape application apparatus comprises a knife blade extending between the forward ends of two arms mounted each on side panels of the frame and cross lengths of tape 5 and a corresponding receiving plate, and the tape is cut by this knife blade and receiving plate. If it is attempted in such prior art apparatus to sharpen the knife blade by reducing the thickness of the blade for cutting the tape more easily, the knife blade tends to be bent in cutting and therefore is unusable. Therefore, there is a certain limit in reducing the thickness of the blade. Besides, since the blade is relatively thick, a gap tends to take place between the engaging portions of the blade and the receiving plate and this imposes an obstacle to facilitating cutting of the tape. Moreover, if the knife blade is damaged even partly, the tape is left uncut in this portion so that the entire knife blade must be replaced.
It is, therefore, an object of the invention to provide a pavement-marking tape applicator capable of fine adjustment of the amount of tape feeding and also capable of preventing slackening of tape in front of an applicator roller.
It is another object of the invention to provide a pavement-marking tape applicator capable of cutting pavement-marking tape very easily.
It is still another object of the invention to provide a pavement-marking tape applicator of improved efficiency which has comprehensively overcome the above described problems in the prior art.